The digital processing of hearing aids has brought about many functional improvements. Among these, noise reduction and directionality have been particularly important for improving the hearing of speech sounds in daily life. Reviews of studies examining the effectiveness of each function found that while noise reduction was useful for improving the hearing of speech sounds in daily life as evaluated subjectively by the hearing aid wearer, no clear improvement was observed in the results of speech intelligibility testing in noisy environments. The opposite was true for the directionality, which was associated with improvement in the results of speech intelligibility testing in noisy environments, while the wearer reported no subjective improvement in the ability to hear speech sounds in daily life. Both functions are present in almost all currently available hearing aids and are automatically adjusted. Further improvements in these functions are expected in the future, but there is also a need to develop methods to evaluate them.

 The results of Clinical Assessment for Attention (CAT) in 16 patients (age: 16 to 29 years, mean age: 21.4 years, 6 males and 10 females) with listening difficulties (LiD) were analyzed retrospectively. The results showed that 1) the detection rate of abnormal findings on CAT was not high, but abnormal findings were detected more frequently in auditory tasks than in visual tasks, and 2) individual differences in attention assessed by the auditory task of CAT were significantly correlated with binaural separation, monosyllabic intelligibility in noise, and word comprehension in a cocktail party environment in LiD patients. The significance and limitations of CAT as an attentional function assessment test for LiD patients, as well as the relationship between attentional function and listening difficulty symptoms in LiD patients, are also discussed.

 A questionnaire survey of hearing aid (HA) stores was conducted to investigate the current status and problems of the HA supply system in Japan. Stores were categorized as those selling fewer than 100 or more than 100 HAs per year and any differences in their responses were examined. The results revealed that most of the stores that sold less than 100 units were dual-use stores. In addition, the staff composition, store facilities, and HA fitting procedures were more extensive in stores that sold more than 100 units per year. Furthermore, most of the stores that answered the question, “Neither the measurement of the HA amplification characteristics, hearing thresholds in the sound field, nor real-ear measurement is conducted, ” were stores that sold less than 100 units per year. It is hoped that equipment will be developed that will allow HA amplification characteristics, hearing thresholds in the sound field, and real-ear measurements to be performed more inexpensively and easily, and that all stores will be able to provide more appropriate HA fittings at lower costs in the future.

 The auditory processing test (APT) was developed to identify the symptoms of auditory processing disorder (APD/LiD), in which patients have difficulty in hearing conversations despite showing normal results in conventional hearing tests, such as standard pure tone audiometry. However, it takes a total of about 3 hours to perform all of the published APTs, which is burdensome for both patients and medical institutions. We attempted to reduce the time required for APT by identifying test items that are most frequently found to be abnormal in patients with APD/LiD. Based on this information, we proposed a shorter version of the APT by removing items with overlapping objectives and those with extremely low standard values due to excessive difficulty. APD/LiD were classified for according to items that fell below the standard values in this abbreviated version of APT. We found that patients with suspected APD/LiD could be evaluated more quickly by focusing on the following tests: history taking or screening tests for developmental disorders and psychiatric disorders, FAPC, Obuchi 's SSQ, standard pure tone audiometry, speech audiometry at 60 dBSPL, and the short version of the APT.

 We investigated the correlation between speech perception scores and subjective evaluation in hearing aid (HA) users using 67-S, 57-S monosyllable, and iCI-2004 word lists. The subjects were divided into two groups: the good speech-perception group (n=40) and the poor speech-perception group (n=16) . There were no significant differences in age or pure tone average between the two groups. The good-speech perception group showed a weak correlation either in “speech sounds” under the good conditions or under the bad conditions. In the poor speech-perception group, correlations were found for words under both the “good conditions” and “bad conditions, ” although the correlations were nothing for 57-S and for 67-S monosyllables under either condition. Since the subjective evaluation used in this study has been proposed in a guideline to measure the satisfaction level with speech perception in the daily lives of HA users, it may be reasonable to conceive that the word scores would be better correlated than the monosyllable scores. Thus, the word test is recommended, particularly for HA users with poorer speech perception. For users with good speech perception, an undernoise condition might also be required to avoid a ceiling effect in a quiet environment.